Furnace wall



` u-g. 25, 1942. R, M, HARDGRQVE 2,293,735

FURNACE WALLv Filed Aug. 1, 1940 Patented AAug. 25, 1942 UNITED sTATEs PATENT OFFICE- 2,293,735A URNACE WALL Ralph M. Hardgrove, Westeld, N. J.,assignor to The Babcock & Wilcox Company, Newark, N. J., a corporation of New Jersey v Application August 1,1940, Serial No. 349,378

2 Claims.

This invention involves an improvement in furnace walls or other boundary surface structures subjected to high temperatures.

In a more specific sense, the invention relates to a furnace wall including spaced wall cooling tubes with studs secured thereommetallic plates forming backing-up members between successive tubes, and refractory material installed as a plastic and molded against the plates and the tubes.

The invention improves the original installation of stud tube furnace walls. by eliminating the necessity of the removal of temporary backing-.up strips and it facilitates the repairs of such furnace walls by making it unnecessary to remove casing sections and thermal insulation employed exteriorly of the wall tubes. The invention also permits stud tube walls to be expeditiously installed in positions too close to a group of convection heat exchange tubes (or other means) to permit of access to that side of the wall adjacent the group.

The invention will be better understood from the following description which refers to the accompanying drawing showing preferred embodiments.

In the drawing:

Fig. 1 is a section of a stud tube furnace wall including the illustrative backing-up plates;

Fig. 2 shows a furnace petition wall in vertical section, an arrangement of convention tubes being illustrated in proximity to that wall; and

Fig. 3 is a transverse section of a furnace wall involving a modification of the Fig. 2 wall.

The furnace partition wall illustrated in Fig. 2 of the drawing is adapted to be exposed to high temperature furnace gases on both sides, and on one side that wall is in such proximity to a bank-of convection tubes that there is no substantial access to the wall on that side. The wall includes the spaced and horizontally arranged tubes l|ll5 which are preferably connected into a fluid system such as the circulation system of a steam generator. Each of the tubes is provided with rows of studs Ii-Zll disposed on opposite sides thereof and preferably welded thereto, or at least secured to the tubes in good heat transfer relationship. y

After the studded tubes are secured in their illustrated positions and the tubular loops 25-3|-, forming a bank of convection tubes, are arranged as shown, metallic plates 35-39 are moved into the spaces between .the stud tube Wall and the bank of tubes. These plates preferably possess passed between adjacent tubes to the position shown, and the installation of the illustrative structure may be further facilitated by the sliding of the strips 35-39 between the ends of the tubes and then along the studded portions of the tubes so that the inter-tube spaces are substantially filled by the plates.

The plates are held against the studs nearest the bank of tubes 253I and are then tackplastic condition, is molded or tamped against such flexibility that they may be sprung and 65 the plates 35-39 and the tubes. During this operation, it will be appreciated that the refractory material is molded into pockets which are formed by the tubes and plates, and that itis also molded around the studs so that the latter are embedded in the refractory material. Thus. the .refractory material may be considered as doubly anchored in its operative position between the tubes, and it is disposed in such extensive contact with the metal cooled by the fluid in the tubes that excessive melting away of the refractory material will be avoided.

Fig. 1 shows what may be termed 'an exterior furnace wall with tubes lll-I5 arranged in the manner of the above described tubes-and similarly provided with opposite rows of studs vdii-49. Plates 50-54, similar to the above described plates, are also similarly secured between the successive tubes ll-IS.

Exteriorly of the tubes of the Fig. 1 furnace wall is a layer of insulating material of an intermediate degree of heat resistance, and exteriorly of this layer is a stratum 62 of thermal insulation to prevent any substantial heat loss from the furnace to the atmosphere.

Theexterior insulating strata GII-62 may bev held in their operative positions by a sheet metal casing 64, which, at distributed positions, may be secured to the tubes. Y

' The material of the insulaiu'ng layerv 6l is .usually such that it will not stand the molding.

compactng, or tamping which is involved in a positioning ofthe high temperature refractory 6B in the pockets between yadjacent tubes, and it has previously been necessary to remove casing 64 and the insulating strata and i2 when it became necessary to replace even small sections of such a wall as that shown in Fig. 1. This is eliminated in the repairof the illustrative wall construction by thel use oi.' the plates ll-ll. These plates are'maintained in their operativo positions by securing them to the studs, and are strong enoughto withstand the tamping or compacting necessary to mold the semi-plastic refractory 68 into the pockets between the tubes.

The wall embodiment illustrated in Fig. 3 of the drawing includes tubes such as those shown at 'il and 1I, which are formed in the shop with the studs and the plates welded thereto. The studs 'l2-1 8 are arranged in rows grouped on opposite sides of the tubes in the manner also illustrated in Figs. 1 and 2, and each tube has plate sections 80 and 8l welded thereto at the rear of the tube and in a substantially tangential relationship. These plates are of such width that their free edges are disposed in close proximity and the tubes are arranged in wall forming relationship. The tubes may be held in such relationship by the use of short rod sections 90 disposed between the facing ends of studs extending from adjacent tubes, and tack-welded thereto; This arrangement of elements is one in which the backing-up plates'are automatically positioned, when the tubular wall units Aare secured in their operative relationships and it is also a wall construction which permits the high temperature refractory 92 to be tamped or molded into pockets between the tubes in a manner similar to that above described.

Although the invention has been described with reference to the details of the preferred embodiments illustrated in the drawing, it is to be understood that the invention is not limited to all the details thereof. It is rather to 4be taken as of a scope commensurate with the scope of the pockets formed by said plates and successive tubes and anchored therein by the tubes and the studs, said refractory material being molded around the studs and against said plates and tubes.

2. In fluid heat exchange apparatus. a row of spaced tubes defining a wall adapted to be advantageously disposed close to a group' o f convection tubes, metallic studs secured to said wall tubes and extending into the spaces between agi;V jacent wall tubes, metal plates so formed as'to close the spaces between adjacent wall tubes and fit against the studs thereon, the plates being welded to the studs, and refractory material illiing the pockets formed by adjacent wall tubes and the intervening plates with the studs extendmg into said refractory.

RALPH M. HARDGROVE. 

